This circuit, with 1 A output, was found in a 1975 documentation. The transistors admit equivalents and the transformer has windings according to the voltages being worked.
This circuit uses a TL071 to differential amplify the signals from a microphone and thus reduce...
With this circuit, found in a 80s Popular Electronics, it is possible to use two ordinary phones in a...
This circuit was found in an American publication from the 1980s. The circuit generates pulses from...